allow unofficial builds with DCHECK and DLOG disabled

build/common.gypi

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 183 matching lines @@
       'linux_lsb_release%': '<(linux_lsb_release)',
 
       # Set to 1 to enable fast builds. Set to 2 for even faster builds
       # (it disables debug info for fastest compilation - only for use
       # on compile-only bots).
       'fastbuild%': 0,
 
       # Set to 1 to enable dcheck in release without having to use the flag.
       'dcheck_always_on%': 0,
 
+      # Set to 1 to make a build that logs like an official build, but is not
+      # necessarily an official build, ie DCHECK and DLOG are disabled and
+      # removed completely in release builds, to minimize binary footprint.
+      # Note: this setting is ignored if buildtype=="Official".
+      'logging_like_official_build%': 0,
+
       # Disable file manager component extension by default.
       'file_manager_extension%': 0,
 
       # Disable image loader component extension by default.
       'image_loader_extension%': 0,
 
       # Python version.
       'python_ver%': '2.6',
 
 
@@ skipping 540 matching lines @@
     'linux_fpic%': '<(linux_fpic)',
     'chromeos%': '<(chromeos)',
     'enable_viewport%': '<(enable_viewport)',
     'enable_hidpi%': '<(enable_hidpi)',
     'enable_touch_ui%': '<(enable_touch_ui)',
     'use_xi2_mt%':'<(use_xi2_mt)',
     'file_manager_extension%': '<(file_manager_extension)',
     'image_loader_extension%': '<(image_loader_extension)',
     'fastbuild%': '<(fastbuild)',
     'dcheck_always_on%': '<(dcheck_always_on)',
+    'logging_like_official_build%': '<(logging_like_official_build)',
     'python_ver%': '<(python_ver)',
     'arm_version%': '<(arm_version)',
     'armv7%': '<(armv7)',
     'arm_neon%': '<(arm_neon)',
     'arm_neon_optional%': '<(arm_neon_optional)',
     'sysroot%': '<(sysroot)',
     'system_libdir%': '<(system_libdir)',
     'component%': '<(component)',
     'use_titlecase_in_grd_files%': '<(use_titlecase_in_grd_files)',
     'use_third_party_translations%': '<(use_third_party_translations)',
@@ skipping 1266 matching lines @@
                   'release_extra_cflags': '-g1',
                 },
               }],
             ],
           }], # clang!=1
         ],
       }],  # fastbuild!=0
       ['dcheck_always_on!=0', {
         'defines': ['DCHECK_ALWAYS_ON=1'],
       }],  # dcheck_always_on!=0
+      ['logging_like_official_build!=0', {
+        'defines': ['LOGGING_IS_OFFICIAL_BUILD=1'],
+      }],  # logging_like_official_build!=0
       ['win_use_allocator_shim==0', {
         'conditions': [
           ['OS=="win"', {
             'defines': ['NO_TCMALLOC'],
           }],
         ],
       }],
       ['enable_gpu==1', {
         'defines': [
           'ENABLE_GPU=1',
@@ skipping 2513 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }